(1) Field of the Invention
This invention relates generally to communications and, more particularly, to satellite broadcast systems.
(2) Background Art
A proposed satellite digital audio radio system (SDARS) supports multiple audio and data program channels (program channels) for broadcasting CD-like music and talk shows to mobile and fixed receivers. Illustratively, the system provides for the transmission of 100 program channels.
Consequently, there is desired a transmission frame structure for efficient transport of these channels.
A transmission frame structure is presented for a satellite digital audio radio system (SDARS). In accordance with the invention, an SDARS transmitter processes N program channels into M clusters, each cluster representing k program channels, where M greater than 1, N greater than M, and (k)(M)xe2x89xa6N. The SDARS transmitter further partitions each cluster into J cluster segments and interleaves the cluster segments from each cluster for transmission, where J greater than 1.
In an embodiment of the invention, an SDARS transmitter provides a broadcast transmission signal including a time division multiplex (TDM) mode of transmission and a coded orthogonal frequency multiplex (OFDM) mode of transmission. The SDARS transmitter provides a transmission signal that supports four transport mechanisms or traffic channels: (1) multiple audio and data program channels (program channels), (2) a cluster control information channel (CC), (3) a global control information channel (GC), and (4) a cluster synchronization channel (CS). In particular, the SDARS transmitter processes 100 program channels into 5 clusters, each cluster comprising GC and CS information, along with a program cluster comprising 20 program channels and CC information. The SDARS transmitter further partitions each cluster into 255 cluster segments and interleaves the cluster segments from each cluster for transmission.